border-1px($color)
	position relative
	&:after
		display block
		position absolute
		left 0px
		bottom 0px
		width 100%
		border-top 1px solid $color
		content ' '
		
bg-image($url)
	background-image url($url + '@2x.png')
	@media (-webkit-min-device-pixel-ratio: 3),(min-device-pixel-ratio: 3)
		background-image url($url + '@3x.png')
		